Theta Digital Casablanca III, Руководство пользователя

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Step by Step Speaker Configuration
Casablanca III contains a comprehensive set of speaker configuration settings. These settings are believed to be the
most complete ever offered in a home theater component and should allow any speaker to perform optimally
regardless of speaker type. It is important to bear in mind that the following procedure is merely a guideline and that
room acoustics, speaker design/quality, music/film type, and personal preferences all have a part in these settings.
Please note that the menu and parameter names described herein are the ones shown on the front panel VFD and not
the OSD (On Screen Display). Using the Setup menu map diagram on page 13 in this manual is recommended.
There are four major steps to be taken in setting up your Casablanca III. In recommended sequence, they are:
Speaker Configuration & Crossovers: permits proper signal routing internally in the Casablanca III and proper
blending of main and subwoofer signals. Enables all speakers present in the system.
Individual speaker levels: compensate for different speaker and amplifier efficiencies.
Delays: compensates for different speaker distances from the listening position.
Input Specific Setup: All parameters that are specific to an individual input select button are then programmed.
Each step plays a pivotal role in the overall sonic result and should receive equal attention and care in adjustment.
Speaker Configuration & Crossovers
Crossovers are most commonly located in a speaker cabinet. Their purpose
is to keep energy at certain frequencies from reaching specific speaker
elements (drivers), [e.g. keeping unwanted bass energy from the tweeters
(see diagram at right).] Home theater applications use a crossover in the
surround processor to send low pass information to a subwoofer and limit the
low pass information sent to the main speakers. The purpose of this section,
SPEAKER CONFIGURATION , is to properly set up the Casablanca III’s
internal crossovers for optimal sound as well as enable all speakers in the
system.
In this manual, a Speaker Set is defined as one or more speakers that are
manipulated via a common parameter. For example, the crossover
parameters for both the front left and right speakers are manipulated in the front left/right configuration submenu since
the desired effect for the left speaker is also appropriate for the right. The other speaker ‘sets’ in the Casablanca III
are the [surround left and right], the [side left and right], the [center] and the [center surround]. The speaker sets will
be delimited by [ ].
The full speaker configuration is stored separately for each of the 12 input select buttons. This procedure will guide
the user to set all configuration parameters for input # 1, and then copy these parameters to all other input select
buttons.
In the Speaker configuration submenu, buttons 1 - 5 will access additional menus to setup a particular speaker or set of
speakers. Button 6 will turn on the side speakers, if configured in the system. In each speaker set’s configuration sub
menu, pressing button # 5 will allow a change of the crossover type for that speaker set. There are three settings for
the crossover type. They are: "Phase Perfect"; "Butterworth"; and "Linkwitz-Riley". Each crossover type requires
different settings that are applicable to that type only. The Front [Left/Right], [Center], [L-R Surround] and [Center
Surround] speaker configuration submenus contain a separate setup submenu for each of the three crossover types.
It is recommended that each of the three crossover submenus be set up similarly for each speaker. The user can then
audition each crossover type to determine which sounds best for their system.
The following crossover type descriptions will help the user to better understand the sonic consequences and
advantages of each:
Phase Perfect
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This is a term coined for a type of crossover wherein the low pass portion is derived from the high pass. First, a high
pass Butterworth crossover is performed. This gives two resulting signals: the high pass and the original, unaltered
signal. Then, the high pass signal is subtracted from the original input signal, resulting in the low pass signal, which is
usually routed to the subwoofer. A positive attribute of this type of crossover is that if the high and low pass signals
are added together, an exact replica of the original input signal results, thus the term "phase perfect". A potentially
negative attribute of this type of crossover is that, due to phase relationships and vector mathematics, higher order
filters (12, 18, 24 dB/octave) always produce 6dB/octave low pass slopes, in terms of electrical energy sent to the
subwoofer. The high pass portion will have the expected 6, 12, 18 or 24 dB /octave slope. Due to this phenomenon,